After Some Breast Cancer Treatments, Risk for Other Health Conditions May Rise

A recent study suggests that while women are living longer after treatment for breast cancer, they may be at greater risk of developing certain health conditions as they age.

The study, published in the Journal of Cancer Survivorship, helps inform older women about lifestyle changes that may reduce their risk of developing osteoporosis, heart disease and high blood pressure.

Background

Comorbidities are health conditions that develop in addition to the main diagnosis of breast cancer. Though not related to the cancer, in some instances they may emerge as long-term side effects of treatment.

Past studies suggest differences in survival rates after breast cancer may be due in part to comorbidities not related to cancer stage at diagnosis. Given this, German researchers wanted to find out what factors could trigger the onset of three of the most common long-term conditions — osteoporosis, high blood pressure and heart disease — in older women treated for breast cancer.

Design

A total of 2,542 women between 50 and 74 years old were interviewed in person or by phone about their physician-confirmed health conditions before and after they were found to have breast cancer. The women answered questions twice: once within an average of 4 months after breast cancer diagnosis and again almost 6 years after diagnosis.

Researchers gathered information about tumors and treatments from medical records. They also noted information about race and sex, lifestyle factors and levels of education.

Results

Researchers found that:

• women treated with an aromatase inhibitor, a hormonal therapy used to help prevent hormone-positive breast cancer from returning, were more likely to develop osteoporosis, or weakening of the bones. They had twice the risk when their body mass index, BMI, was less than 22.5.
  • BMI is a measure of body fat, based on height and weight in adults. Numbers between 18.5 and 24.9 are considered in the healthy range for an adult 20 years or older. The Centers for Disease Control and Prevention offers a tool to help calculate BMI.
• older women with higher BMIs and women who received trastuzumab (Herceptin) had an increased risk of developing high blood pressure
  • Because the number of people who received trastuzumab was small, more research is needed to confirm this finding.
• women who had a BMI higher than 30 had almost twice the risk of high blood pressure compared with women with a lower BMI
• women with a higher BMI and those treated with an AI had greater risk of heart disease

Limitations

Researchers relied on women remembering when they were diagnosed with other health conditions rather than getting the information from medical records. Though they noted the women seemed to be well able to provide information about their other conditions, memory may not match fact. In addition, the study did not track how severe the co-existing health conditions were.

What this means for you

This study suggests age, weight and type of treatment may influence your risk of developing high blood pressure, heart disease or osteoporosis after a breast cancer diagnosis. Maintaining a healthy weight and regular exercise may help prevent heart disease and high blood and keep your body strong. Work with your physician to decide on an exercise program that is right for you.

If you are taking an aromatase inhibitor or received trastuzumab, talk with your physician about steps you can take to reduce possible side effects, such as osteoporosis or heart disease. In many cases, the benefit of taking these treatments outweighs the potential risk of side effects and measures can be taken to lessen risk. As part of your follow-up plan, your doctor may screen you for these conditions.

To learn more about the risk of comorbidities in older women treated for breast cancer, read “ Breast Cancer After 60” in our national newsletter, “Insight.”

Obi N, Gornyk D, Heinz J et al. Determinants of newly diagnosed comorbidities among breast cancer survivors.  Journal of Cancer Survivorship. 2014; doi: 10.1007/s11764-013-0338-y